This invention has to do with a locking cable hanger system for use in the solar, mining, and electrical industries. In solar, mining, and electrical industries there is a need for electrical cables to extend from a power or signal source to a location of application. Such cables are usually supported by a messenger wire that are themselves independently structurally supported and strung along the planned cable route. In solar plants, direct current wires attach first to the solar panels and then run to combiner boxes before extending further to power inverters. In addition, alternating current power cables are used to power the motors that control the trackers, devices that rotate the solar panels to follow the sun in order to obtain maximum power during daylight hours.
Prior to 2014, AC and DC cables could be bundled immediately adjacent to, and touching, one another in a wire management system for the solar panels. In the new National Electric Code of 2014, the AC and DC cables must not be immediately adjacent to one another, but must have a degree of separation from one another. Power carrying cables have a tendency to induce errors or interfere with the signal wires that are located in close proximity to them. This new requirement also applies to other applications outside the solar power industry, such as the mining and electrical industries.
Because of the increased use of trackers in solar power plants, there is increased use of category five cables and other data wiring. This type of control wiring is used to give power plant operators feedback from the solar power plant array on what angles the panels are stationed, and what the proper angle should be to maximize power output from the sun. This data and information is constantly monitored to obtain maximum power output from the thousands of solar panels in the solar power plant. The type of wiring used in collecting data is sensitive to cables used for AC and DC power and because of that sensitivity, data wiring cannot be bundled with power cables and must be supported by a separate carrier that is at least 1 inch away from all power cables.
In solar power plants, mining and other electrical applications, there are various sized wires and bundles of wires with an almost unlimited variety of wire bundle sizes. Bundle size is becoming very important in the manufacture of hangers to accommodate these various sizes, especially in multiple carrier hangers.
The cable hanger has a unique locking arm attachment section which has a closed loop spiral for a secure lock on the messenger wire. In the past, hangers had open loops or modified open loops on the top attachment section which could easily fall off if the hanger were bumped or hit during the wire loading process. In a solar plant there is a recent move to tracker systems which utilize more wiring than previously fixed in place systems. There is also the new NEC code which went into effect Jan. 1, 2014, which states that all AC and DC wiring must now be separated in any hanging or support system. Because of these changes, the wire management systems are much more complex, especially given the vast number of wires involved in a utility scale solar power plant. With these changes, the hangers are initially installed on the messenger wire with a captive top spiral loop, and the bundles of cables are loaded separately in the carrier or carriers of the hanger. This process continues until all individual cables and bundles of cables are supported in the hangers. In the process of loading cables, the hangers are constantly bumped and jostled as they are loaded with bundles of cables. All styles of hangers presently on the market can easily fall off the messenger wire because they are only hanging by one open loop, and they can fall off when bumped during cable installation. Cambria County's Association for The Blind And Handicapped is a new and improved captive locking arm idesigned to securely grip the messenger wire so the cable hangers stay in position during the entire loading process and will not fall off when bumped or knocked. After all cables are loaded, the other top attachment end of the cable hanger is then squeezed and locked on the messenger wire.
The new NEC code requires any cable support system to have supports that are spaced at no greater than 12 inch intervals. This applies to cable trays, hangers or all other types of cable support systems. The old-style hangers with their open style loops can fall off easily during installation and also easily slide out of their 12 inch spacing when loading the cables. This is a more serious problem when you consider that there are tens of thousands of hangers being installed in the desert heat which can reach 120° F. Any wasted labor is a high additional cost in this environment. The new unique captive closed loop locking arm on CAB's cable hangers securely retains the hanger in place even when bumped or knocked around during the cable installation process. This improved captive engagement will also keep cable hangers securely in position on the 12 inch centers and eliminate the need to reposition hangers on 12 inch centers after all cables have been loaded into the carriers of the hangers.
A major factor affecting labor costs during installation of cables is how easily the electrician can load the cables and bundles of cables in the hangers in the stifling heat of the desert where solar power plants are usually located. All styles of cable hangers presently on the market will easily swing from side to side as they are initially suspended on the messenger wire. This means an electrician must take one hand and properly align the hanger in a 90° perpendicular orientation to the messenger wire in order to load the cables or bundles of cables in the hanger with the other hand. This two handed process of aligning the hanger increases the time necessary to load cables over the thousands of feet of messenger wire with the hangers on 12 inch centers. The newly designed captive top locking arm of the CAB cable hanger addresses this problem by always maintaining the hanger at a 90° orientation to the messenger wire on initial installation. The newly designed top locking arm totally eliminates any lengthwise swinging or traveling movement from side to side and allows the electrician to use both hands for the loading of cables and cable bundles. The new design feature will save many hours of labor in the field and improve efficiency by maintaining 12 inch centers on the messenger wire when installing all types of cables or cable bundles.
The secure gripping top locking arm is a major improvement in hangers which can save hundreds of hours of labor on a large scale solar power plant. It greatly improves the efficiency of electricians and the quality of cable installations. Three major advantages of the new secure top locking installation arm are: the elimination of hangers falling off the messenger wires during loading, maintaining hangers at the proper orientation to the messenger wire for ease of cable loading, and maintaining the cable hanger on the messenger wire at the specified spacing for improved quality and speed of installation